This invention relates to multiple spindle screw thread machines, and more particularly to improved apparatus for releasably mounting threading rolls on the outboard attachments to the machine. More specifically, this invention relates to a device for releasably and reversibly securing a threading roll on its rotatable support shaft, which is carried in the usual manner by a thread roll supporting arm.
The U.S. Pat. No. 4,617,816, which is owned by the same company to which this application has been assigned, discloses a thread rolling attachment of the type with which this invention is generally concerned. An attachment of the type disclosed in the above-noted patent includes a pair of thread roll supporting arms, which are pivotally mounted intermediate their ends on a yoke, to be forced into rolling engagement with opposite sides of a piece of rotating bar stock in order to form threads in the stock. The arms are actuated by a wedge element which is manipulated by a fluid pressure operated piston.
Typically threading rolls of the type described are subjected to an enormous amount of pressure when they are forced against diametrally opposite sides of the rotating bar stock in order to form a pattern, such as threads, in the peripheral surface of the stock. For example, it heretofore has been customary releasably to secure a threading roll of the type described to one end of a rotatable shaft, which is mounted for rotation in a bore located in the outer of the pivotally mounted roll supporting arm. However, the means heretofore employed for removably securing the roll to the shaft has been such that it normally is a rather time-consuming operation to mount a threading roll upon, or to remove it from, its supporting shaft. Moreover, such mounting means has not enabled one readily to reverse the position of the threading roll on the shaft in order to maximize use of the roll.
Accordingly, it is an object of this invention to provide improved means for releasably securing a threading roll on the supporting shaft carried by a roll supporting arm in a screw machine outboard attachment of the type described.
Still another object of this invention is to provide relatively simple and inexpensive means for quickly and easily a threading roll onto or removing it from a roll supporting shaft of the type described.
Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawing.